A switched communication network transfers data from source to destination through a series of network nodes. Switching can be done in one of two ways. In a circuit-switched network, a dedicated connection is established through the network and is held for as long as communication is necessary. An example of this type of network is the traditional telephone system.
A packet-switched network, on the other hand, routes data in small pieces called packets, each of which proceeds independently through the network. In a process called stored-and-forward, each packet is temporarily stored at each intermediate node, then forwarded when the next link becomes available. In a connection-oriented transmission scheme, each packet takes the same route through the network, and thus all packets usually arrive at the destination in the order in which they were sent. Conversely, each packet may take a different path through the network in a connectionless or datagram scheme. Since datagrams may not arrive at the destination in the order in which they were sent, they are numbered so that the destination user can reorder them properly.
A data packet is routed through the network primarily according to its destination address. In order to determine the correct subsequent network the router has to convert the destination address of a data packet into a corresponding next hop physical address (i.e. the outgoing port of a router). This task is called “address lookup” and is carried out as a part of the more complex “packet processing” task. The destination address is stored in a packet header. The packet header is a portion of a packet that precedes the actual data, containing source and destination addresses, error checking and other fields.
Packet processing, in addition, includes carrying out tasks like classification, filtering or load balancing, which may, based on multiple fields contained in the packet (not only the destination address), further influence the “address lookup” and the entire treatment and alterations applied to the packet in a router. For example, decide on specific QoS (Quality of Service) treatment of the packet, its mapping onto an MPLS (Multiprotocol Label Switching) label, discarding it or sending it to a control point in case of filtering or splicing with another TCP (Transmission Control Protocol) connection in case of load balancing.
In the last decade the amount of data packet traffic being communicated over communication networks has grown exponentially especially the Internet a well-known member of the family of connectionless packet-switched networks. In some circumstances the data packet traffic reaches such a level that conventional routers reach their limit. Since the performance of a router is crucial to the number of packets that can be transmitted through a communication network or from one communication network to another, a slow router can cause a backlog of data packets, or, in other words, a backlog of data packets is caused by an overload of the router. This might also happen because of an enormous amount of packets arriving at the router in a short period of time. Such a scenario might be produced if a huge number of users send messages over the network roughly at the same instant of time.
This might happen in various situations, for example, during a major sport event, when a large amount of visitors seeks to retrieve additional information about the event from a related web site. Furthermore, it has to be expected in systems providing interactive information exchange, such as Internet, television or radio game shows. In such shows the participants, which can practically be all viewers or listeners of the respective show, are normally asked to respond to some action in the show, e.g., by answering a question, making a selection or by voting for something or somebody. Having a large number of participants, the communication system used for data communication might be overloaded because of the large number of responses being returned in a very short period of time.
A need thus exists for a method and a system that reduces the peak load of data transfer through the networks for interactive information exchange.